When constructing a home or a facility, it is well known to provide garage doors that utilize a motor to enable the opening and closing of the door. Motors may also be coupled with other types of movable barriers such as gates, windows, retractable overhangs and the like. An operator is employed to control the motor and related functions with respect to the door. The operator receives command input signals for the purpose of opening and closing the door from a portable wireless remote transmitter, from a wired or wireless wall station, from a keyless entry device or other similar device. It is also known to provide safety devices that are connected to the operator for the purpose of detecting an obstruction so that the operator may then take corrective action with the motor to avoid entrapment of the obstruction.
To assist in moving the garage door or movable access barrier between limit positions a user-actuated remote radio frequency (RF) or infrared transmitter is used to actuate the motor and move the door in the desired direction. As such, these remote devices allow for users to open and close garage doors without getting out of their car. Additionally, such remote devices may be provided with other features, such as the ability to control multiple doors, lights associated with the doors, and other security features. As is well documented in the art, the remote devices and operators may be provided with encrypted codes that change after every operation cycle so as to make it virtually impossible to “steal” a code and use it at a later time for illegal purposes. An operation cycle may include opening and closing of the barrier, turning on and off a light that is connected to the operator and so on.
Although remote transmitters and like devices work well, they are cumbersome and distracting to the driver, as his or her hands are occupied with maintaining a controlled grip over the steering wheel, or gear shift while exiting the garage or driveway. As such, the potential damage resulting from the inadvertent actuation of the remote transmitter while the vehicle is in the path of the access barrier is increased. Furthermore, the switch mechanism of the remote device typically becomes worn after a period of time and requires replacement. To overcome these disadvantages, various systems for the “hands-free” operation of the remote transmitter have been developed. Such hands-free systems comprise a mobile transmitter that communicates, via various mobile signals, with a base operator that is configured to actuate an access barrier, such as a garage door, between opened and closed positions. Specifically, the mobile transmitter is generally carried by a carrying device, such as a vehicle, and is configured to transmit mobile signals to the base operator so as to move the access barrier between open and closed positions, depending on the relative position of the carrying device to the base operator, as well as other criteria.
Many hands-free systems utilize a mobile transmitter that is carried by a suitable carrying device, such as a vehicle, which communicates with the barrier operator, through signals periodically sent to the mobile transmitter, such that when no return signal is received, the barrier operator commands the access barrier to close. Unfortunately, such a manner of operation allows the closing of the access barrier to be potentially initiated with the user out of visual range of the door, which may result in safety concerns, as the user may be led to believe that the door has closed, when in fact an obstruction has caused the door to open and remain open allowing unauthorized access to others.
Therefore, there is a need in the art for an operator system that automatically initiates only the closing sequence for an access barrier depending upon the change in position of a carrying device. In addition, there is a need for an operator system that utilizes a mobile transmitter that automatically closes an access barrier based on the change in the angular position of a carrying device as it is moved. Furthermore, there is a need for an operator system that provides a mobile transmitter that includes an activity sensor, such as an accelerometer, so as to automatically close an access barrier when a carrying device has reached a predetermined linear distance from the access barrier. Still yet, there is a need for a mobile transmitter that includes an accelerometer that is capable of discriminating between unintended movement, such as the accidental movement of the mobile transmitter within a carrying device, and movement resulting from the acceleration of the carrying device, so as to conserve the transmitter's power source and properly control the movement of the access barrier. In addition, there is a need in the art for a mobile transmitter that automatically emits somewhat periodic signals that are received by the operator so as to automatically open an access barrier when the carrying device approaches the closed access barrier. And there is a need for a mobile transmitter that provides user-changeable sensitivity adjustment of the mobile open signal. Furthermore, there is a need for a mobile transmitter that includes a transceiver, to provide two-way communication between the mobile transmitter and the base operator solely to facilitate the selection and learning or re-learning of an optimum mobile remote transmitter communication frequency.